40T Heavy-Duty Rear Sprocket for Mini Bikes - High-Speed & High-Torque Performance This premium 40-tooth rear sprocket fits popular mini bikes like Coleman CT100U/CC100X, Baja DB30, Mega Moto MMB80/105, Motovox MBX10, and more, compatible with #40/#41/#420 chains. Made from high-strength steel with gold-zinc plating for corrosion resistance, it handles extreme loads and high RPMs for lasting durability. Optimized for 212cc+ engines, its precision-cut teeth ensure smooth power transfer, reduce chain wear, and prevent slippage—perfect for racing, hill climbing, and high-speed runs. The 40T design boosts torque and acceleration while minimizing engine strain. Upgrade your mini bike with this heavy-duty sprocket for better performance, smoother rides, and long-lasting reliability on any terrain!